BACKGROUND:The development of international clinical practice guidelines offers an opportunity to harmonize evidence-based care across diverse health-care systems but presents substantial logistical, methodological, and implementation challenges. These challenges are particularly pronounced for nontraumatic osteonecrosis of the femoral head, a condition characterized by heterogeneous disease biology, evolving diagnostic criteria, and limited high-certainty evidence. METHODS:This article summarizes key lessons learned during the development of the first international, evidence-based clinical practice guidelines for osteonecrosis of the femoral head led by the Association Research Circulation Osseous. RESULTS:Key lessons emerged across multiple domains, including optimization of panel structure and workflow, effective use of virtual collaboration platforms, early engagement of methodological experts, refinement of literature search and data abstraction approach, and staged formulation and approval of recommendations. Additional insights highlighted the need to anticipate global variability in resources, language, and clinical context, underscoring the value of resource-stratified recommendations, early planning for translation and cultural adaptation, incorporation of patient values and preferences, and linkage of guideline recommendations to measurable quality indicators to assess real-world uptake and impact. CONCLUSIONS:The lessons learned emphasize that international guideline development should adopt a life cycle approach extending beyond publication to promote equitable adoption, continuous refinement, and meaningful improvements in patient care worldwide.

Background/Objectives: Diagnostic evaluation and management of nontraumatic osteonecrosis of the femoral head (ONFH) vary substantially. This systematic review was conducted to inform development of the Association Research Circulation Osseous (ARCO) clinical practice guideline for diagnosis and treatment of ARCO stages I to III ONFH. Methods: We searched MEDLINE, EMBASE, Web of Science, SCOPUS, Global Index Medicus, and the Cochrane Library for studies evaluating imaging modalities and treatments for adult ONFH. We assessed risk of bias using the QUADAS-2, the ROB-2, and the ROBINS-I tools; conducted meta-analyses using random-effects regression; and evaluated certainty of evidence using GRADE methodology. Results: Among 36 included studies, 18 addressed diagnostic test accuracy and 18 addressed comparative effectiveness of treatments. Magnetic resonance imaging (MRI) demonstrated the highest pooled sensitivity (0.91; 95% confidence interval (CI), 0.87 to 0.94) and specificity (0.96; 95% CI, 0.87 to 0.99) for ONFH diagnosis. Bone marrow edema and grade 2+ joint effusion on MRI differentiated symptomatic versus asymptomatic disease. Computed tomography and MRI better detected subchondral fractures than plain radiography. Very low-grade evidence suggested lower rates of femoral head collapse with core decompression plus bone marrow concentrate compared with core decompression alone (pooled relative risk [RR], 0.55; 95% CI, 0.36 to 0.83), and with vascularized versus non-vascularized bone grafting (RR, 0.35; 95% CI, 0.14 to 0.84) over a ≤5-year follow-up. Based on three non-comparative case series, osteotomies might have a lower risk of collapse over a 10- to 20-year follow-up, but this needs to be evaluated in future comparative research. Inconsistent outcome reporting hindered treatment outcome pooling. There were no comparative studies that evaluated observation only versus intervention in asymptomatic disease or strategies for monitoring treatment response. Conclusions: Evidence supporting optimal imaging modalities and early joint-preserving interventions remains limited and predominantly observational, underscoring the need for high-quality comparative studies with consistently defined core outcomes to guide clinical decision-making.

➢ Nontraumatic osteonecrosis of the femoral head should be suspected in patients who are <50 years of age who have persistent hip pain despite normal radiographs.➢ Bilateral involvement is common; magnetic resonance imaging (MRI) of the contralateral hip is recommended.➢ MRI is the most sensitive modality for detecting early disease.➢ Femoral head sphericity is assessed on anteroposterior, lateral, and 30º view radiographs.➢ Small pre-collapse lesions have the best prognosis. Large lateral lesions and subchondral collapse predict rapid progression.➢ Systemic risk factors and multifocal disease should be actively evaluated.➢ Joint-preserving procedures are most effective before structural collapse.➢ Total hip arthroplasty remains the most reliable treatment after femoral head collapse.

BACKGROUND:Nontraumatic osteonecrosis of the femoral head (ONFH) can lead to major disability in patients of all ages. It presents at various levels of severity and can be either symptomatic or asymptomatic. There is a vast array of management strategies. Treatment is often subject to physician bias. Clinical practice guidelines that are broad-based, internationally developed, consensus-driven, and strictly evidence-based are needed. The aim of this guideline by the Association Research Circulation Osseous (ARCO) was to develop international evidence-based recommendations to assist physicians and patients in managing ONFH. METHODS:ARCO convened an international, multidisciplinary guideline panel that was balanced to minimize potential bias from conflicts of interest. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was utilized, including GRADE Evidence-to-Decision frameworks. The panel prioritized clinical questions, defined criteria for the systematic review of evidence, evaluated the statistical analysis, and, by consensus, approved recommendation statements, which were then subject to external review by content experts and stakeholders (a health policy-maker and a patient). RESULTS:The panel agreed on 12 recommendations for the diagnosis, evaluation, and management of ONFH. CONCLUSIONS:Key recommendations of these guidelines require accurately staging ONFH and determining when pain may be due to ONFH. They establish principles for optimal decision-making by assessing the quality of evidence backing various treatments and identifying numerous areas for additional investigation. CLINICAL RELEVANCE:This international evidence-based guideline provides standardized recommendations for the diagnosis and management of nontraumatic ONFH. It synthesizes all available evidence using GRADE methodology and offers practical, consensus-supported guidance for accurate staging, imaging selection, treatment decision-making, and the identification of patients who would benefit from joint-preserving interventions. The guideline supports clinicians in reducing practice variation, improving diagnostic accuracy, and optimizing treatment pathways for patients with ONFH.

Background Nontraumatic osteonecrosis has historically been attributed to vascular insufficiency, leading to oxygen and nutrient deprivation and subsequent bone death. However, terminology used to describe this condition remains inconsistent and often fails to capture its complex pathogenesis. Terms such as “avascular necrosis” and “ischemic necrosis” may inappropriately emphasize vascular mechanisms, potentially limiting diagnostic and therapeutic approaches. Methods We performed a comprehensive review of the literature to examine the evolution of terminology for nontraumatic osteonecrosis and to evaluate the breadth of underlying pathophysiologic mechanisms. Particular attention was given to the clinical and conceptual implications of commonly used terms. Results Evidence indicates that disrupted bone homeostasis represents the final common pathway in the development of nontraumatic osteonecrosis, which may result from vascular or vascular-independent mechanisms. Continued use of terms that focus solely on vascular insufficiency may bias clinical management toward revascularization strategies, overlooking other contributory factors. Conclusions The term “osteonecrosis” more accurately reflects the multifactorial nature of this condition. Broader adoption of this terminology may foster a more comprehensive understanding of disease mechanisms and stimulate the development of innovative, multimodal treatment strategies.

BACKGROUND:Osteonecrosis is a debilitating condition characterized by bone tissue death and disrupted vascular circulation, most commonly affecting the femoral head. This study aimed to assess the epidemiology and surgical trends of hip osteonecrosis in the United States using a comprehensive national database, as well as to review the current literature on historical and contemporary surgical trends for patients who have osteonecrosis of the femoral head (ONFH). METHODS:Data from a research network (2015 to 2024) were used to identify patients diagnosed with ONFH using International Classification of Diseases, 10th revision, Clinical Modification codes. Patients who had osteonecrosis at other sites were excluded. Baseline demographics, comorbidities, and geographic distribution were characterized. Treatment trends were evaluated within 1 and 5 years of diagnosis. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a systematic review across three databases, resulting in a total of five articles. Articles met the inclusion criteria if they provided data regarding surgical trends of patients who have ONFH over at least a 10-year period. RESULTS:From the recent database, of 61,903 patients who have hip osteonecrosis, the majority were of idiopathic etiology (78.1%, n = 48,365). Men comprised 52.1% (n = 25,197) of the idiopathic cases, and the age at diagnosis ranged between 40 and 72 years. The Southern United States had the highest prevalence of hip osteonecrosis (42%), followed by the Northeast (30%). Corticosteroid use was the most common risk factor (75%, n = 36,274), followed by dyslipidemias (49%, n = 23,699) and nicotine use (27%, n = 13,058). Total hip arthroplasty (THA) was the predominant treatment modality within 1 year (22.6%, n = 10,931) and 5 years (25.2%, n = 12,187). In our systematic review, we found that THA was the most common procedure performed for patients who have ONFH, and joint-preserving procedures generally declined over the studies' time periods. However, joint-preserving procedures were more commonly performed in younger patients and appeared to increase in incidence over the studies' time periods. Studies using a database from Asian countries used more joint-preserving procedures than studies using a database based in the United States. CONCLUSIONS:Hip osteonecrosis accounts for 40% of the osteonecrosis burden in the United States, and corticosteroid use was identified as the most common risk factor. Surgical interventions, particularly THA, are the primary modality of treatment, with limited use of other surgical and nonsurgical management. Our systematic review confirmed that the incidence of THA has increased over the years compared to joint-preserving procedures, although the latter has become more common in younger patients. There also appears to be considerable geographic variation in surgical trends, as patients in South Korea and Japan are more likely to undergo joint-preserving procedures. These findings underscore the need for consensus-driven treatment guidelines. LEVEL OF EVIDENCE:III.

BACKGROUND:Multifocal osteonecrosis (MFON) is defined as the diagnosis of osteonecrosis in at least three distinct anatomic sites that can occur consecutively or concurrently. It is important for arthroplasty surgeons to be aware of and manage these patients appropriately. There is a paucity of data surrounding the characterization, diagnosis, and treatment of MFON. The purpose of this investigation was to systematically review the literature to identify: (1) clinical presentation/epidemiology, (2) pathophysiology, (3) diagnostic modalities, and (4) treatment guidelines/algorithms of MFON. METHODS:Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a systematic review across three databases, resulting in a total of 12 articles. Articles met the inclusion criteria if they provided data regarding: (1) clinical presentation/epidemiology, (2) pathophysiology, (3) diagnostic modalities, and (4) treatment guidelines/algorithms of MFON. RESULTS:There are many etiologies of MFON, though autoimmune diseases such as lupus and prior use of corticosteroids are most commonly implicated in the disease. The femoral head is the most common anatomic site involved, though other joints such as the knee, shoulder, and ankle can be commonly affected. Diagnosis is reserved for standard radiography and whole-body magnetic resonance imaging (MRI) for screening, with regional MRI reserved for additional staging of the disease. Treatment is similar to standard single or oligofocal osteonecrosis and involves joint preservation procedures if the joints are found before collapse and the use of arthroplasty following collapse if nonoperative modalities fail. CONCLUSIONS:Although MFON is a rare clinical condition, it is one that arthroplasty surgeons should be aware of and meticulously screen for in their patients. It is defined as the presence of osteonecrosis in three or more distinct anatomic sites either concurrently or consecutively. Arthroplasty surgeons should be wary of patients who have osteonecrosis and should be meticulous in screening these patients for multiple joint involvement.

Objective. This paper aims to estimate asymptomatic hip osteonecrosis prevalence in SLE patients using MRI examination and to determine the prevalence among higher risk subpopulations. Materials and Methods. PubMed, Embase, Cochrane, and SCOPUS were searched from inception to May 9th, 2023. Studies on patients who were clinically diagnosed with systemic lupus erythematosus without reported symptoms attributable to hip osteonecrosis were included. Two independent reviewers extracted data and assessed the risk of bias. Data collected from each study include the study year, the number of hips screened, the number of hips with osteonecrosis, demographics, laboratory data, medications, follow-up time, radiological protocols, and MRI-based osteonecrosis detection and grading criteria. Results. Eleven eligible studies including 503 participants (15–35 years old; 74–100% female) with SLE were identified. Significant risk of bias was determined in one study. The overall prevalence of osteonecrosis of the hip was found to be 14% (184/1006 hip joints, 95% confidence interval: 7–22%, number needed to scan: 7.1). SLE patients who received corticosteroid treatment had a higher prevalence of asymptomatic hip osteonecrosis (18%) compared to non-corticosteroid users (0%, p-value < 0.01). Additionally, meta-regression results revealed that daily corticosteroid dose was associated with increased prevalence of asymptomatic osteonecrosis (0.5%/milligram, p-value < 0.01). Conclusions. The high prevalence of asymptomatic hip osteonecrosis in SLE patients raises concerns about the timeliness of interventions. The limitations of this study include a relatively low number of identified studies; and one study lacked full-text availability.

Background The decision to undergo total knee arthroplasty (TKA) is complex, requiring patients to consider the risks and benefits of surgery. It is the clinician’s responsibility to educate patients on their treatment decisions. Patient decision-making aids are a tool for clinicians to utilize with their patients to improve their patients' understanding of their condition and treatment options. With increased emphasis on patient-centered healthcare, implementation of a shared decision-making aid in adult reconstruction clinical practice may help patients make better informed decisions. Purpose Given that the orthopaedic surgery clinic is the primary setting where a patient decides whether to pursue non-operative treatment versus surgery, patients and clinicians in this setting may benefit from the use of a shared decision-making tool (SDMT). The primary goal of this study was to evaluate the utility of a patient-specific SDMT on the patient’s decision regarding knee osteoarthritis (OA) management. Methods A randomized prospective clinical trial was conducted to evaluate the impact of a SDMT regarding treatment for knee OA. Patients were randomized to an intervention arm with the implementation of a patient-specific SDMT or a control arm with a standard of care (SOC) clinic appointment without the use of the tool. The impact of the SDMT was assessed by evaluating patients on Patient-Reported Outcome measures, and their attitudes towards non-operative and operative interventions. Results Both the patient-specific SDMT and control groups demonstrated a statistically significant increase in post-visit understanding of their disease progression. Patients in the SDMT group demonstrated a significant increase in the proportion of patients who would be “extremely likely” to pursue non-operative treatment post-visit. Comparisons between SDMT and control groups demonstrated a significant inclination for the SDMT cohort to enroll in non-operative, conservative management such as corticosteroid or hyaluronic acid injections. Conclusion Use of a patient specific customizable SDMT tool in an adult reconstruction clinic positively impacted patient attitudes toward receiving non-operative treatment for OA and, more importantly, patient understanding of disease post-visit. Trial Registration: This randomized controlled study (ID: NCT05411939, Registered 04/15/2023 at clinicaltrials.gov) was approved by the institutional review board at our university (HIC# 2000032637) and used the CONSORT checklist.

Abstract Purpose Popliteal artery laceration is a devastating complication in total knee arthroplasty (TKA). Its anatomic position relative to the tibia has been studied using ultrasound or magnetic resonance imaging. This is the first study performed in a laboratory using radiographic measurements to determine if increased flexion and subluxation of the knee increase the distance between the tibia and popliteal artery. Methods The femoral artery was infused with radiopaque dye in six cadavers. The knee was placed in two different degrees of flexion and three of subluxation. The radiographic distance between standardized markers in the posterior tibia and popliteal artery was measured. Results The average distance from the tibial peg to the popliteal artery at 90° of flexion increased from 0% to 50% to 100% subluxation. The increase was statistically significant (Friedman test p = 0.016). The contrast between neutral and 100% subluxation was statistically significant (Sign test p = 0.031). At 115° flexion, average distance from the peg to popliteal artery significantly increased as subluxation increased (Friedman test p = 0.05). In three specimens, at 115° of flexion and 100% subluxation, a line perpendicular to the axis of the tibia, failed to intersect the popliteal artery. The measured distance increased from 90° to 115° of flexion at a given degree of subluxation, but this difference did not reach statistical significance. Conclusions Increasing flexion and subluxation of the tibia results in increasing distance between the cut plane of the tibial plateau and popliteal artery and decreases risk of laceration. Level of Evidence Not applicable.